Track and print out the apps and clients that are inhibiting Gnome session actions like log out, user switching, suspending or idle/dpms/screensaver, under Linux.

track_session_inhibitors.py

#!/usr/bin/python
"""
Print out the apps and clients that are inhibiting session actions like log out, user switching, suspending or idle.

%InsertOptionParserUsage%

Example:
 track_session_inhibitors &

Todo:
 Remember info about inhibitors and clients, for display when the are removed

 describe flags with mnemonics.  Consider using bitstring package:
  http://packages.python.org/bitstring/walkthrough.html

Flags:
 1: Inhibit logging out
 2: Inhibit user switching
 4: Inhibit suspending the session or computer
 8: Inhibit the session being marked as idle

References:
 http://people.gnome.org/~mccann/gnome-session/docs/gnome-session.html#org.gnome.SessionManager.Inhibitor
 http://www.devtech.com/inhibitapplet
"""

import sys
import traceback
from gi.repository import GObject
import dbus
import dbus.mainloop.glib
import pynotify
import logging

__author__ = "Neal McBurnett <http://neal.mcburnett.org/>"
__version__ = "0.1.0"
__date__ = "2012-07-12"
__copyright__ = "Copyright (c) 2012 Neal McBurnett"
__license__ = "GPL v3"

def inhibitor_dump(inhibitor_id):
    status = "%s " % inhibitor_id
    inhibitor = bus.get_object('org.gnome.SessionManager', inhibitor_id)
    interface = inhibitor.Introspect()

    # import pdb; pdb.set_trace()	# to figure out if there is anything to show for InhibitorRemoved

    if interface.count("org.gnome.SessionManager.Inhibitor") > 0:
        try:
            clientId = inhibitor.GetClientId()
        except dbus.exceptions.DBusException, e:
            clientId = "(null)"

        status += "flags=%x,  x11id=%d: %s \"%s\" %s" % (inhibitor.GetFlags(), inhibitor.GetToplevelXid(), inhibitor.GetAppId(), inhibitor.GetReason(), clientId)
    else:
        status += "(null)"

    if len(sys.argv) <= 1:
        n = pynotify.Notification ("SessionManager Inhibitor Watch", status)
        n.show ()

    return status

def client_dump(client_id):
    status = "%s " % client_id
    client = bus.get_object('org.gnome.SessionManager', client_id)
    interface = client.Introspect()

    # import pdb; pdb.set_trace()	# to debug

    if interface.count("org.gnome.SessionManager.Client") > 0:
        # print client.GetAll('org.gnome.SessionManager')   # why does this always fail with UnknownMethod: Method "GetAll" with signature "s" on interface "(null)"?
        try:
            # Why does this always fail?
            clientId = client.GetClientId()
        except dbus.exceptions.DBusException, e:
            clientId = "(null)"
            #logging.exception("Exception with GetClientId")

        status += "process=%d: %s \"%s\" %s" % (client.GetUnixProcessId(), client.GetAppId(), client.GetStatus(), clientId)
    else:
        status += "(null)"

    if len(sys.argv) <= 1:
        n = pynotify.Notification ("SessionManager Client Watch", status)
        n.show ()

    return status

def session_inhibitor_signal_handler(id):
    logging.info(inhibitor_dump(id))

def session_client_signal_handler(id):
    logging.info(client_dump(id))

if __name__ == '__main__':
    if len(sys.argv) >1:
        # for now treat any argument as a request to just print current inhibitors and clients to stdout, and then exit
        logfile = None
    else:
        logfile = "/var/log/session_inhibitors"

    logging.basicConfig(level=logging.DEBUG, format='%(asctime)s\t%(message)s', filename = logfile, filemode='a' )

    logging.info("Start find_session_inhibitors")

    if not pynotify.init ("summary-body"):
        logging.error("pynotify.init failed")
        sys.exit (1)

    dbus.mainloop.glib.DBusGMainLoop(set_as_default=True)

    bus = dbus.SessionBus()
    proxy = bus.get_object('org.gnome.SessionManager','/org/gnome/SessionManager')

    blockers = proxy.GetInhibitors()

    for objectpath in blockers:
        logging.info(inhibitor_dump(objectpath))

    clients = proxy.GetClients()

    for objectpath in clients:
        logging.info(client_dump(objectpath))

    if len(sys.argv) >1:
        sys.exit(0)

    bus.add_signal_receiver(session_inhibitor_signal_handler, "InhibitorAdded", "org.gnome.SessionManager")
    bus.add_signal_receiver(session_inhibitor_signal_handler, "InhibitorRemoved", "org.gnome.SessionManager")
    bus.add_signal_receiver(session_client_signal_handler, "ClientAdded", "org.gnome.SessionManager")
    bus.add_signal_receiver(session_client_signal_handler, "ClientRemoved", "org.gnome.SessionManager")

    logging.info("Start listening for signals")

    mainloop = GObject.MainLoop()
    mainloop.run()